Hi Henrrry,
         I had a similar type problem.   It was traced back to a DB2 backup.
It was a matter of the TSM server getting a bad size estimate and not
properly saving enough disk space.  It would then have to keep going though
the internal space allocation process.  It made TSM look very surgy in its
response time and CPU utilization went way up.   I am not sure why your MVS
people see going to tape as the problem.  But the FREEZING looks very
similar.
Matt

 -----Original Message-----
From:   Henrry Aranda [mailto:harango AT HOTMAIL DOT COM]
Sent:   Friday, December 06, 2002 2:26 PM
To:     ADSM-L AT VM.MARIST DOT EDU
Subject:        TSM S/390 performance

Hi list,
environ is TSM server 4.1.2.12 on S/390 with 3494 library connected
via FICON, 3590E tape drives, 60+ SQL Servers using TDP 2.2 and Oracle
server on AIX 5.1 with 1,5TB of backup data (no Oracle TDP is being used),
the 390 is connected via gigabit ethernet to the clients, the issue is when
the backup sequence starts at night, the TSM server process "freezes" from
time to time, that is, it doesn4t receives data nor responds to command
line, it lasts for some seconds and then it comes to live again, have you
seen this kind of behavior before? it doesn4t prevent the backups to
complete but affects the total backup window and we are trying to isolate
the error, 390 guys say that it seems that this "contention" occurs when TSM
tries to access 3590 drives, is it normal? did I misconfigured something?

Any comment will be helpful.

Thanks

Luis Tapia


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